ES2320774T3 - WATERPROOF DISPERSION POLYMERS OF MODIFIED LONG CONSERVATION SILANO. - Google Patents

Abstract

Disclosed herein is a process for preparing a shelf-stable, one-pack, silane modified (meth)acrylic latex interpolymer composition, wherein the process comprises continuously adding at least a portion of a mixture comprising at least 0.5 mole percent of a vinyl silane comprising hydrolyzable groups and up to 99.5 mole percent of a (meth)acrylic monomer to water and a surfactant in a reaction vessel, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 throughout the reaction, while simultaneously hydrolyzing from about 10 to about 60% of the hydrolyzable groups of the vinyl silane.

Description

Silane aqueous dispersion polymers Long-lasting modified.

The present invention relates to copolymers of latex (meth) acrylic and processes for elaboration of these.

How it was used here, the terminology "(meth) acrylic" is intended to mean "acrylic or methacrylic. "

There is an extensive prior art on the free radical copolymerization of unsaturated silanes with organic comonomers, in systems that carry solvent as well as also in systems that carry water. Although not completely absent, shelf life problems and problems due to high levels of silane incorporation, they cannot be Ignore the importance in non-aqueous systems. In the systems that carry water, most of the technique ignores the issues of shelf life, or not trying to supply long shelf lives, particularly when higher concentrations of silanes For specialized applications, this system can be Use shortly after synthesis.

Dispersion polymers are well known aqueous (commonly latex). Some general references include:

Waterborne and Solvent Based Acrylics and their user Applications, ed. P. Oldring and P. Lam, Volume 1 of Surface Coatings Technology, John Wiley and Sons, New York, 1997 , especially Chapter II, and;

Resins for Surface Coatings, Volume I, Acrylics and Epoxies, H. Coyard, P. Deligny and N. Tuck, John Wiley and Sons, New York, 2001 .

These references describe the typical synthesis conditions, initiating techniques, comonomers, end-use properties and conditions of application.

Latex can be supplied with properties top for use in coatings, sealants, and adhesives by incorporating organofunctional alkoxy silanes in the polymer. Superior properties include resistance to common household chemicals and solvents, as well as resistance to latex paints for scrubbing with cleaning agents homemade. In sealants, a sealant can be obtained from such so that it produces unions that are resistant to the environment, are flexible, and do not flow after curing in place. These properties arise from crosslinking of polymer chains in the latex after application and the flow or coalescence of the latex. The inclusion of silanes provides an effective mechanism to create "self-crosslinking" latex polymers, which do not they need the addition of a separate crosslinking agent - this that is, they are "one package" systems, not "two systems" packages. "There are also chemicals that do not involve comonomers containing silicon that achieve some benefits of The self-cross-linking latex systems of a package. The silicon based technologies (silane) offer superior strength to UV degradation and the environment compared to most of the other technologies.

This technology -based on comonomers of alkoxysilane - has been practiced to some degree for years in a Limited number of latex applications. However, there are deficiencies in what has been achieved to date, particularly in relation to combining good stability and good low cure temperature.

First - alkoxy silanes react with the Water. Hydrolysis of alkoxy groups bonded to silicon, such Like methoxy or ethoxy groups, it happens easily and produces alcohol free, such as methanol or ethanol. Remaining in the atom of silicon after hydrolysis is a group -OH, namely a silanol The condensation of two silanoles to form a bond SI-O-SI, with the release of water, It is thermodynamically favored. Unfortunately, hydrolysis and premature condensation can destroy a silane and make a this siloxane polymer before it has a chance to incorporate into a latex in a uniform and well controlled way during polymerization. Hydrolysis and condensation after of the incorporation of the silane can prematurely cross-link the latex polymers during storage, resulting in solidification and gelation of the latex or the product that They contain latex in the bowl. If crosslinking occurs within of the latex microparticles, it may not be obvious gelation, but the particles will not flow together and do not coalesce after the application. This may result in the loss of gloss (for coatings) or brittle films that have no integrity when exposed to solvents, or sealants, with poor integrity. On the other hand, if it can be controlled This process could produce a latex that uses this chemical to crosslink the polymer system after application, to Give superior properties.

In some applications, it is possible to heat the substrate after application of a latex coating that Contains silane The "stew" or baked items Coated with paints is well known. This heat can be use to "activate" the silane chemistry described, always and when chemistry can be kept "dormant" while the modified silane polymer system is stored in the Bookshelf waiting for use. However, warming uses energy and some substrates may not be able to withstand heat.  Catalysts, such as acids, bases, and compounds Metallic (tin, titanium derivatives, etc.) can be used to catalyze the reaction. This is usually achieved by using a two-package system, which is less desirable than the one-system package. Two-pack systems require control of the amount of the additive, and they can have an "open life" very Limited or "pot life" after agent addition catalytic.

It is desirable to have a package system that cure under ambient conditions after application and, at At the same time, do not react prematurely during storage. For practical use, a product, such as a coating, must be stable during storage for many months or years. This It is an extremely difficult goal to achieve, due to needs conflicting reactivity and stability. Any approximation which is done in the use of an extremely unreactive silane that can survive storage due to its low reactivity faces the problem of how to make non-reactive silane Become reagent subsidiarily. Achieve this without heat or a Catalyst is very difficult.

In some cases, the goal of stability in shelving and curing at room temperature in a system of a package can be achieved when using concentrations extremely low silanes. The speed of condensation of the silanoles to form a siloxane reticulum is proportional to the square of the concentration of silanol groups. (The speed equation It is second order in silanol concentration). So, the condensation reaction may be slower by reducing the silane concentration, and the effect is very strong because of the dependence of the concentration square. However, if one you want to obtain a higher level of properties and faster cure of system after application, it is desirable to increase the silane concentration above the levels that are typically stable through the use of silane concentrations very low, that is, above small fractions of a percentage by weight in the polymer.

As indicated, try to control the chemistry that occurs in the latex polymer system is not simple or direct, with several that can influence the results including:

one.

Temperature. The polymerizations are typically performed at elevated temperatures, such as 60 to 65 ° C. Storage can be at room temperature. The application is usually at or near room temperature, but the Applied coating can be heated.

2.

Water concentration While the Water concentration is high in the aqueous phase, approximately 55 moles per liter, will be much less in the oil phase. Speeds of hydrolysis and condensation are influenced by the water concentration

3.

Solubility. A hydrolyzed silane, which it carries silanoles, it is much more soluble in water than silane not hydrolyzed A vinyl silane has a different proportion of those polar and non-polar groups than a silane with a substituent of methacryloxypropyl on silicon.

Four.

Chemical structure The vinyl silanes monomers tend to be more reactive to hydrolysis than silanes with the same alkoxy groups in which silicon does not It is directly attached to a vinyl group (unsaturated). One time polymerized in an organic copolymer, the alkoxy groups on silicon that is derived from a vinyl silane, and that is, in turn, directly on the polymer structure, they will tend a reduced reactivity due to steric shield by chain dough polymer The same factor reduces the reactivity for condensation as well as for hydrolysis. In comparison, the silicon derived from methacryloxypropyl silane in several atoms away from the structure, and its chemistry is less influenced by steric factors

5.

Environmental variables The facts, such as the pH and the concentration of the acidic or basic groups or  Metal ions and nucleophiles in the reagents will influence the silane chemistry in different ways, depending on the type of silane, whether hydrolysis and / or condensation are considered, and Similar.

The complexity of these interactions makes extremely difficult to predict the results of a synthesis before of actually running the reaction and tests of results.

Commercially available silanes that are can be copolymerized by induced addition polymerization by free radicals with organic acrylic and vinyl comonomers, and that are available in production quantities sufficiently Great to be practical for large-scale industrial use, they are vinyl functional silanes or methacrylate functional silanes. A An example of a functional vinyl silane is vinyltrimethoxysilane. A example of a functional methacrylate silane is methacryloxypropyltrimethoxysilane. As a class, vinyl silanes functional are substantially less expensive per pound than methacrylate silanes.

In a mode for industrial applications On a large scale, functional vinyl silanes are used at a cost by alkoxy silane group (or by silanol). In another mode, both the lower cost per pound of vinyl silanes (in relation to methacrylate silanes) as well as their lower equivalents  by weight per alkoxy silane group, can be used for a commercially viable technology. Due to the selective nature of the reactivity of the double bond during copolymerization with vinyl and methacrylic or acrylic monomers, vinyl silanes they can be easily copolymerized with vinyl monomers, such as vinyl acetate Vinyl monomers do not readily copolymerize with double bonds of (meth) acrylate and should be used special care to achieve the uniform incorporation of any vinyl monomer (whether this is a silane or not) in polymers that They consist mainly of methacrylate or styrenic monomers. However, for many end uses, they can be used more expensive organic methacrylate or acrylate comonomers, because the resulting polymers have superior durability, resistance to environmental factors, higher temperatures of glass transition, and other superior properties, even in the absence of silane comonomers.

When the reaction rate is considered to incorporate silane in the polymer, it should also be considered  the rate of hydrolysis of the silane before and after the incorporation into the latex polymer, as noted above. In general, trialkoxyvinylsilanes hydrolyze faster than (meth) acryloxyalkyltrialkoxysilanes as monomers free. Once the silanes have been incorporated into the polymer, the trialkoxy silane residue will tend to be less reactive in hydrolysis and condensation due to the steric shield that arises from the location of the silicon directly on the structure of the polymer.

Thus, in total, the problem to be solved is how to achieve a silane-modified polymer dispersion polymer (latex) system, from a package, not perishable using vinyl silanes with organic comonomers of
(meth) acrylic, although achieving silane concentrations above 1% by weight, up to 5% or even more, which will cure a solvent and resistant chemical at room temperature, and that can be stored for an extended time, for example at least six months and, preferably, more than one year, more preferably up to three years, without premature crosslinking to a degree sufficient to make it substantially less useful for coating applications.

United Kingdom Patent No. 1,407,827 describes a process for making vinyl dispersions stable coagulated-free aqueous substances that have improved adhesion. In this process, (i) (a) one or more monomers selected from vinyl esters of carboxylic acids, esters of acrylic acid, and esters of methacrylic acid, and optionally up to 25% by weight (with relation to the total weight of component (i) of one or more of others simple olefinically unsaturated water-insoluble monomers, or (b) a mixture of styrene and up to 40% by weight (in relation to the mixture) of butadiene, they are copolymerized with (ii) from 0.3 to 5% in weight (in relation to the total weight of component (i)) of a Silicon compound of a given general formula. Polymerization it is carried out at a temperature in the range from -15 to + 100 ° C in an aqueous phase, and in the presence of a radical initiator free soluble in water and an emulsifier and / or colloid protective.

U.S. Patent No. 3,575,910 describes silicon-acrylate copolymers, aqueous emulsions of these copolymers, latex paints containing the copolymers and articles of manufacture that have a coating which contain the copolymers.

U.S. Patent No. 3,706,697 describes that the polymerization of the aqueous acryloxyalkyl emulsion alkoxysilane, alkyl acrylic esters, and optionally others vinyl monomers produce copolymers that are curable at low temperatures The silane can be introduced to the polymerization after a portion of the other monomers polymerizes. Be says heat cure improves solvent resistance of cured films as they are molded of latex and that Catalysts that cure silanol improve the speed of cure.

U.S. Patents Nos. 3,729,438 and 3,814,716 describe latex polymers comprising a dispersion of a interpolymer selected from the class consisting of (A) a copolymer of vinyl acetate and a hydrolysable vinyl silane and (B) a vinyl acetate terpolymer, an ester, for example, acrylic ester, maleic ester or fumarate ester, and hydrolysable vinyl silane, as well as well as crosslinked polymers derived therefrom. The Latex polymers are said to have utility as coatings surface protectors and as vehicles for formulations of painting.

U.S. Patent No. 4,716,194 describes that the remobility of pressure sensitive adhesives based on acrylate is substantially improved by adding to them of a small amount of an organofunctional silane monomer.

U.S. Patent No. 5,214,095 describes stable aqueous emulsion copolymers with functionality of controllable siloxane crosslinking. These copolymers are prepared through a concurrent free radical and a polymerization of cationic initiated emulsion of at least one initiable monomer with free radical, at least one monomer initiable with radical free, at least one linear siloxane precursor monomer, and by at least one bifunctional silane monomer that has both a free radical polymerizable as silicon functional groups. The Copolymers are said to be useful in curable coatings, paints, caulks, adhesives, nonwoven compositions and ceramics and as modifiers, processing aids and additives in thermoplastics, cements and asphalts.

U.S. Patent No. 5,482,994 describes reticles of polymer which are compositions formed by adding an alkoxy unsaturated silane and an emulsion polymer initiator preformed. The polymer lattices are said to have utility as protective surface coatings, adhesives, sealants and as vehicles for paint formulations.

U.S. Patent No. 5,599,597 describes molded of concrete not reinforced or reinforced, for example concrete, with improved corrosion resistance to acids and acid residues, improved permeation resistance to liquids inorganic or organic and gases and improved mechanical stability, produced when molding with machines, for example, in machines of pressure molding or extrusion machines or pressure machines concrete tube, and by allowing the hardening of mixtures of hardened plastic-viscous concrete hydraulic inorganic binders, preferably cement, aggregates and water, where, in the preparation of mixtures of plastic-viscous concrete has been added to last in a positive mixer an effective amount of a dispersion of aqueous plastics based on anionic and copolymers resistant to hydrolysis of ethylenically unsaturated monomers, the minimum film formation temperature (MFT) of which is above the solidification temperature of the concrete mixture, preferably above 23 ° C.

U.S. Patent No. 5,932,651 describes emulsion which copolymerizes a particular crosslinker, that is, a siloxane or silazano, with an organic monomer. An emulsion can form having particles consisting of polymer chains formed of organic monomer. Depending on the crosslinker and the conditions reaction, these emulsion polymer chains can be reticular or non-reticular. Uncrosslinked polymer chains are can crosslink at a later point by adding a suitable catalyst.

U.S. Patent No. 5,994,428 describes core-shell copolymers modified with silane, storage stable comprising a copolymer cover former I of a) from 70 to 95% by weight, based on the total weight of the cover, from C 1 to C 10 alkyl esters of acrylic and / or methacrylic of which from 20 to 80% by weight they have a water solubility of no more than 2 g / l and from 80 to 20% by weight, based on each case in the comonomers, a), has a water solubility of at least 10 g / l, and b) from 5 to 30% in weight, based on the total weight of the roof, of one or more water soluble, functional, ethylenically monomers unsaturated, which include a proportion of 25 to 100% by weight, with base in the comonomers b), of unsaturated carboxylic acids, and a core II forming copolymer of one or more monomers c) from the group of vinyl esters, mono or dicarboxylic esters monoolefinically unsaturated, vinyl aromatic compounds, olefins, 1,3-dienes and vinyl halides, where the cover does not contain silane compounds and the core comprises one or more silane compounds d) from the silane mercapto group alone or in combination with olefinically silicon compounds unsaturated, hydrolysable.

U.S. Patent No. 6,130,287 describes a emulsion polymer comprising a protective colloid and a component of silane functionalized which is of a formula structural given.

WO98 / 35994 describes emulsion polymers that they are said to have an excellent resistance combination of blocking, water stain resistance and stain resistance of ethanol. These polymers are made from a mixture of monomers that includes a monomer with a highly polar group that includes a carboxylated or sulfonated monomer, or both, a monomer that has a group of hydrolysable silicon, and a non-functional monomer that you can select to provide a formation temperature of Minimum desired film. These polymers are said to be useful in paints and coatings applications.

European Patent Publication No. 0 327 376 describes copolymers of vinyl esters and silicon monomers, with very low levels of silicon monomer, which are said to be especially suitable as binders for paints of emulsion, giving very good resistance to scrubbing. He vinyltrimethoxysilane is copolymerized with organic comonomers that They comprise at least 40% vinyl acetate. One is expected substantial or complete hydrolysis of the silanes to the silanoles. He pH is not mentioned as a critical variable, and ranges are not indicated pH

Bourne et al ., J. Coatings Technology, 54: 69-82, # 684 (January 1982) describes attempts to obtain stable silane modified latex copolymers from a variety of organic acrylate and methacrylate monomers by copolymerization with various alkoxy methacrylate functional silanes. These attempts have been achieved with failures. A range of pH conditions was attempted with ethyl acrylate as the comonomer. Conditions include starting at a pH 9 or pH 7 and allowing the pH to deviate, as well as a pH 9 or no pH adjustment resulting from gelation (coagulation) during the reaction. The runs made at pH 7 did not coagulate during the synthesis. However, even those preparations give unacceptable levels of clot and inadequate shelf stability.

Marcu et al ., Macromolecules, 36: 328-332 (2003) carried out extensive studies using extraordinary techniques in attempts to obtain emulsion polymers modified with stable silane. These authors attempted to copolymerize vinyltriethoxysilane with butyl acrylate, in order to obtain stable emulsion polymers, they had to reorder the use of a "mini-emulsion" technique. This technique involved the addition of hexadecane to the reaction mixture to form an oil phase that could "protect" the silane from hydrolysis, plus the use of ultrasound to achieve extremely high cutting and agitation. The pH control was mentioned as being prominent in the literature and was used in its work. Experiments were performed using sodium bicarbonate buffer at 1% mol on monomers, at pH 6.5 (page 330, experimental section). Even with these techniques, using the tanda reaction reaction scheme, they were unable to get the silane to copolymerize by the polymerization of free radical addition with the butyl acrylate. Instead, the hydrolysis and condensation reactions of the vinyltriethoxysilane reactions produced some form of oligomer, which eventually reacted with the organic latex polymer, possibly by transesterification or some other heterolytic mechanisms. Control reactions run without the oil phase were also run, and gave poor results.

Cooke et al ., Emulsion Polymerization with Hindered Silane Monomers, presented to Silicones in Coatings III, Barcelona, Spain, March 28-30, 2000, directed the use of highly hindered silanes with reduced hydrolytic reactivity, such as vinyl-tri-isopropoxysilane and methacryloxypropyl-tri-isopropoxysilane, with acrylate or methacrylate comonomers. Additional studies with this type of silane were reported in Silicones in Coatings IV, in Guildford, United Kingdom, May 30-31, 2002. In this work, the use of sodium bicarbonate buffer to control pH is described and established that It is not necessary with vinyl silanes, only with methacrylate silanes. This work did not involve vinyltriethoxysilane.

Many other publications and patents also exist, for example, a review of Silanes in Coatings Technology, published in The Journal of the Oil and Color Chemists' Association, 79: 539-550 (December, 1996). The greater number of publications and patents since 1970 testify to the difficulty of this problem. Many give conflicting advice about conditions, such as pH and reaction conditions, and many involve other reagents, other comonomers, and the like, all of which have the potential to change the complex balance between hydrolysis, condensation, and free radical polymerization in a system with an aqueous phase and a phase
Oily

The descriptions of the above are incorporated here by reference in its entirety.

Summary of the Invention

A (meth) acrylic latex is supplied modified with vinyl silane, for example, vinyltriethoxysilane, under conditions specified by a novel and synthesized process to a specific range of composition that is stable to storage and supply latex systems that experience self-curing that will can cure with solvent resistant films without catalyst or added heat.

In one embodiment, the present invention is directed to a composition that is a latex copolymer (meth) aqueous acrylic, modified by incorporation of hydrolysable groups bearing vinyl silane, such as groups alkoxy, which can be cured at room temperature without adding catalyst after application to a substrate to supply a crosslink, solvent resistant film or object, and which is stable on shelf. In one embodiment, the latex comprises less about 10% and up to about 60% of groups alkoxy derivatives of hydrolyzed vinyl alkoxysilane to release alcohol during polymerization. In another modality, the vinyl silane is a vinyltrialkoxysilane, where the alkoxy functional group It is ethoxy or n-propoxy.

In another embodiment, the present invention is aimed at a process to make this latex that is widely similar to known latex polymerizations, but is unique in that the specific pH range is maintained during the polymerization, wherein the vinyl silane is vinyltriethoxysilane a a concentration of up to 3 moles%, possibly as much as 5 moles%, and greater than 0.5 moles% relative to other monomers. This process deliberately hydrolyzes some of the alkoxy groups silane to release alcohol and form silanoles, but does not produce such high level of silanoles that systems become unstable and will not survive shelf aging.

In contrast to the known technique, which describes pH control during the synthesis of silane-containing latexes in many references to the contrary with many polymer systems different and silanes, and avoid discussions of hydrolysis of silane and / or condensation, in this invention the hydrolysis of silane reactions and additional silane reactions will control for specific desired levels.

More particularly, the present invention is directs to a process to prepare an interpolymer composition of silane modified latex (meth) acrylic from a package, non-perishable comprising continuously adding at least one portion of a mixture comprising at least 0.5 mol percent of a vinyl silane comprising hydrolysable groups and up to 99.5 mole percent of a (meth) acrylic monomer in water and a surfactant in a reaction vessel, wherein said addition is carried carried out in the presence of a polymerization initiator and sufficient buffer to maintain the pH of the reaction in a level of at least 6 through the reaction while simultaneously hydrolyzes from about 10 to about 60% of the hydrolyzable groups of vinyl silane.

In another embodiment, the present invention will be directs a latex interpolymer composition (meth) silane modified acrylic from a package, not perishable prepared by a process that includes adding continuously at least a portion of a mixture comprising at least 0.5 mol percent of a vinyl silane comprising hydrolysable groups and up to 99.5 mol percent of a monomer (met) acrylic in water and a surfactant in a glass of reaction, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 through of the reaction, while simultaneously hydrolyzing about 10 to about 60% of the hydrolysable groups from vinyl silane.

Description of preferred modalities

The invention in one aspect relates to a aqueous (meth) acrylic latex copolymer, modified by incorporation of hydrolysable groups that are vinyl silane, such as alkoxy groups, which can be cured at room temperature or before without adding catalyst after application to a provide a solvent resistant object or film crosslinked that is not yet perishable for a period of time extended.

As used here, which is non-perishable means that it is stable for a period of time extended to room temperature. The non-perishable compositions of silane modified latex interpolymers maintain a significant fraction of its performance characteristics after Storage at room temperatures. The characteristics of performance include crosslinked ambient temperature after application, solvent resistance after cure, and the gloss retention after natural or accelerated wear.

In one embodiment of the invention, the composition It is non-perishable for at least one year at room temperature after natural aging (or in a test equivalent of accelerated aging by those moderately skilled in the polymerization technique and latex formulation). In a second modality, this is stable for six months at temperature environment in natural aging (or in a test equivalent of accelerated aging). In a third mode, this is stable up to three years at room temperature.

The process of the present invention comprises the aqueous copolymerization of acrylate monomers and a vinyl alkoxy silane under conditions that are similar to, but different from, what conventional. The continuous addition of silane with other comonomers, preferably at the beginning of the reaction, it is necessary to incorporate some of the vinyl silane in the polymer by polymerization of free radical addition. If vinyl silane is not added continuously, this will not copolymerize, and may form a a separate siloxane copolymer, which may or may not be attached or of another how to react with the organic polymer during the course of the reaction. As another possibility, vinyl double bonds do not can be reacted from all acrylate monomers that are They have hydrolyzed. While, vinyl silanes can be hydrolyze, to form condensable silanols with non-vinyl groups reagents, and instead a condensed polymer of siloxane or oligomer This results in a non-uniform and undesirable incorporation. of silane, or, in some cases, may result in a physical mixture of two materials - an organic polymer and a siloxane polymer, which It is undesirable.

The vinyl silanes that can be used in the Practices of the present invention include, but are not limited to, vinyl alkoxysilanes, especially vinyl alkoxysilanes where the alkyl functional group of the alkoxy group is major, for example, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyl-tri-n-propoxysilane, vinyl-tri- (methoxyethoxy) -silane, and Similar. Other vinyltri- and dialkoxy silanes can be used under some circumstances, but the reaction is controlled for obtain the desired degree of partial hydrolysis that becomes more hard. The silanes are only substituted with methoxy groups also easily hydrolysable and toxic methanol is released. Alkoxy major silanes, i.e. anterior propoxy, also hydrolysable Slowly they are convenient to use. Secondary alkoxysilanes, such as vinyl tri-isoproxysilane, they are also definitely non-reactive, such as alkoxysilanes  Tertiary Generally, butoxy is also slowly hydrolyzed silanes and cause undesirable odors from released butane. In one embodiment, the silane is vinyltriethoxysilane or vinylmethyldiethoxysilane. In a second mode, the silane is vinyltriethoxysilane.

A wide range of acrylic and methacrylic comonomers common in the art can be employed in the practice of the present invention. For reference, see Waterborne and Solvent Based Acrylics and their End user Applications and Resins for Surface Coatings, Volume I, Acrylics and Epoxies, supra , which also describes process details, optional comonomers, test methods, and conventional process methods that are They can employ. Styrene monomers can easily be included, as they are easily copolymerizable with acrylic monomers, but not with sufficient levels to cause deterioration properties. Styrenic materials, however, are strong absorbers of UV light and can reduce durability in outdoor exposure. Optionally, up to 20% by weight of one or more organic vinyl comonomers may be added, such as vinyl acetate, vinyl propionate, or vinyl neodecanoate (VEOVA?), But preferably at a sufficiently low level to cause deterioration. not significant of the durability properties of the final product. Still other comonomers can be included to a lesser extent, if desired, together with the system that substantially retains its (meth) acrylic characteristics.

In the process of the present invention, a buffer, such as sodium bicarbonate at a level of about 0.4% to about 0.7% of the aqueous phase, It is used to keep the pH in the range less than 6. The levels major and minor shock absorber can be used if they are present the major and minor amounts of acidic material or Basic in the reaction. The reaction typically starts at a pH less than 8, and after 15-20 minutes it drops to a range from 6 to 7, where it is maintained when fed as monomer Additional shock absorber can be added during reaction. If storage stability is not necessary for A given application, acceptable latexes can be produced in preparations that have a lower pH of these levels preferred.

During the reaction process, some of the vinyltrialkoxysilane, for example vinyltriethoxysilane, hydrolyzes, and The amount of alcohol released can be determined. In a modality, the alcohol released is less than 10% and less than 60%. In a second modality, at a level of approximately 19% at approximately 48%, and may vary slightly with the concentration of silane and the selected structure.

The composition produced is a copolymer (meth) aqueous acrylic in which at least 1 mol%, preferably 1 to 5 mol%, more preferably 3 to 5 mol% (approximately 7 to 9% by weight, depending on other comonomers) of Vinyltrialkoxysilane has been incorporated mainly through copolymerization In the examples described here, with the particular comonomers are used, 3 mol% vinyltriethoxysilane which corresponds to 5.2% by weight.

The composition can be characterized additionally for its ability to form a resistant film of crosslinked solvent when applied to the metal panel and Allows you to stand at room temperature for 7 days. The ability to withstand at least double friction 75 MEK (methyl ethyl ketone) is a satisfactory crosslinking measurement. This technique It is described in ASTM D 4752-87 and is well known for those moderately skilled in the coatings technique.

The initiation of polymerization can be carry out by standard methods known in the art, which include but are not limited to redox initiation, thermal initiation, and their combinations

Examples of polymerization initiators, specifically thermal initiators, include but are not limited to the following: peroxides such as hydroperoxides, hydroperoxide t-butyl peroxide di-t-butyl, benzoyl peroxide, benzoyl hydroperoxide, peroxide 2,4-dichlorobenzoyl, and the like; such azo compounds as azoisobutyronitrile (AIBN); inorganic persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate, etc.; t-butyl peracetate; peroxycarbonate of Isopropyl, and their combinations.

Redox initiators are combinations of two or more components that react chemically to form radicals free. Examples of redox initiator combinations include but they are not limited to the following, and their combinations:

Persulfate-bisulfite: persulfates such as sodium, potassium, and ammonium persulfate, with agents of reduction such as sodium thiosulfate, sodium metabisulfate, sodium hydrosulfite, sodium bisulfite, sulfoxylate formaldehyde sodium) and optionally a ferrous salt, for example sulfate ferrous or ferrous ammonium sulfate; Chlorate bisulfite: sodium bisulfite and chlorate potassium; Peroxide-iron: hydrogen peroxide, by example t-butyl hydroperoxide, and a ferrous salt, which optionally includes a reducing agent such as a sugar,  for example dextrose or fructose, with regenerated ferrous ions; Persulfate-mercaptan: a persulfate such as potassium persulfate and a mercaptan such as mercaptan lauryl

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Examples

Examples 1-13 are carried out using the redox initiation method. The examples 14-16 are carried out via the method of thermal initiation

The examples employ aging tests accelerated that are used by those moderately skilled in the latex polymerization and formulation technique, that is, the sample storage at elevated temperatures for stimulate greater storage at low temperatures, such as room temperature. The perfectly exact correlation of accelerated results with room temperature results or in the "real world" that conditions of use are not possible final for all possible specific cases; however, it commonly accepts that a month of storage at 50 ° C generally approximately one year of storage at room temperature, nominally 23 ° C. In the examples, the data is obtained mainly in samples aged at 50 ° C.

The following is a list of the devices that can be used for examples of the invention.

Appliances

800 mL shirt reaction flask (for 300 gram preparations).

Heat fluid circulator

Thermometer

Rod Shaker

Bomb of Measurement for the monomer solution (FMI piston pump RP-G400)

Syringe pump for initiator solutions (syringe infusion pump 22, of Harvard apparatus)

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Examples 1-13

In these examples, the method of redox initiation where reactions are carried out in a temperature between 60 and 65ºC, which in one mode, is the range for The redox initiator system used. However, it can be used any temperature at which initiation methods can be use effectively.

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I. Reagents and materials

Methyl Methacrylate (MMA)

Butylacrylate (BA)

Methacrylic Acid (MAA)

Vinyltriethoxysilane - Silquest® A-151 silane (available from General Electric Company.)

Baking Soda (NaHCO3)

Ferrous Sulfate (FeSO4)

Sodium Sulfoxylate Formaldehyde (SFS)

Potassium persulfate (K 2 S 2 O 8)

Ammonium persulfate [(NH 4) 2 S 2 O 8

T-Butyl Hydroperoxide, 70% by weight in water (t-BHPO-70)

IGEPAL® CA-897 (Rhodia)

ABEX® 2020 (Rhodia)

Deionized water

Ammonium hydroxide

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II. Formulation used in the Examples 1-13 (based on the total of 300 grams)

A. water, optional buffer (sodium bicarbonate), surfactant (s) :

Deionized water

150 g

Shock absorber sodium bicarbonate

quantities varied

IGEPAL CA-987

13.5 g

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B. Monomers :

The monomers are selected in these examples. individuals to maintain a constant percentage of MAA, and a constant ratio of MMA to BA, varies as the content of silane There is no limited limitation involved in the process. For every 100 grams of monomers, the following ratios are used, presented to allow percentage amounts to be views easily. When the synthesis of all 125 grams of monomer is used, the amounts by weight are multiplied by 1.25 to calculate the amount of monomer charged in the examples of job. For example, for a 3 mol% silane incorporation, the amounts of monomers used would be 6.50 grams of vinyltriethoxysilane, 38.50 grams of BA, 78.125 grams of MMA, and 1,875 grams of MAA.

one

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C. Initiators :

2

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III. Synthesis - Examples 1-13

1. 150 mL of deionized water is added in a 800 mL jacket reaction flask, and 13.5 grams of the surfactant and the indicated amount of sodium bicarbonate are added with gentle agitation. The contents are heated at 63 ° C with temperature constant fluid in the jacket while the flask is purged with N_ {2}. The N_ {2} layer is maintained throughout the series.

2. Silane and acrylic monomers (125.2 total grams) are mixed and transferred to an addition funnel separated.

3. The initiator, FeSO_ {4} (1.2 is added grams, 0.15% ac) followed by K 2 S 2 O 8 (0.9 g), with stirring of the surfactant solution prepared in step 1. It Stirring continues for 5 minutes.

4. The first portion of the monomer is added to the flask. 10% of the monomer mixture prepared in step 2 (12.5 grams) and 10% of the SFS solution (0.9 gram) are added to the flask of reaction via two separate pumps during a period of about a minute An exotherm is usually noted. The reaction is allowed to run at a temperature of 65 ° C for 15 minutes maintaining good agitation. The reaction temperature is maintains within 2-3º at 65ºC for the stages 5-7.

5. The rest of the monomer mixture (112.7 grams) and an additional 70% of the SFS solution (10.5 grams) is continuously charged through separate pumps for a period three hours Sometimes a slight viscosity is noticed increased

6. The reaction mixture is stirred for others. 30 minutes later the monomers are fully added and this initiator portion.

7. At this point, the t-BHPO-70 (0.01 grams), followed by the remaining SFS solution (1.8 grams) is added over a period 30 minutes

8. The latex is allowed to cool to temperature ambient. The pH is adjusted to 7.5 using hydroxide solution of ammonium (<10% ac). The latex is filtered using a nylon sieve 200 mesh.

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IV. Results - Examples 1-13

Examples 1, 2, 3, and 4

Latexes are prepared according to the general procedure, using 2 mol% vinyltriethoxysilane, and the indicated amount of shock absorber.

Example 1a and 1b. This preparation takes out in duplicate. Does not involve buffer, and the pH during reaction is allowed to bring it down an initial pH of 4-5, quickly reduced within 15 minutes to less than pH 3 for an additional 3.5 hours of the time reaction.

Example 2. This preparation uses 0.2 grams of sodium bicarbonate buffer (0.13% in the aqueous phase.) The pH during the reaction is allowed to bring it down a Initial pH of 8.5, quickly reduced within 15 minutes at pH 6.5 to 7, and is further reduced to pH 2-3 at end of reaction

Examples 3a and 3b. These preparations by duplicate use 0.25 grams of bicarbonate buffer sodium (0.17% in the aqueous phase.) The pH during the reaction is left decrease from an initial pH of 8.5, it quickly reduces within 15 minutes at pH 6.5 to 7, and is further firmly reduced to pH 3.5 (3a) and 4 to 5 (3b) at the end of the reaction.

Example 4. This preparation uses 1.0 grams of sodium bicarbonate buffer (0.67% in the aqueous phase.) The pH during the reaction is allowed to decrease from an initial pH of 8.5, it is firmly reduced within 15 minutes of pH 8 to 8.5, and it Firmly reduce further to pH 6.5 at the end of the reaction.

Examples 1a and 1b show development acceptable on initial tests within a week of preparation. However, after a year of storage of conservation, substantially deterioration develops.

Example 2 gives the acceptable performance in the tests done, but shows noticeable deterioration after a year.

Examples 3 (a and b) and 4 give development Excellent when done and after a year. After a year, it has reduced the initial development of better conservation of the Example 3 and the development of Example 4 is equal or greater. In 2 mol% (3.5% by weight) vinyltriethoxysilane, avoid low pH extremes during the reaction that is sufficient to obtain acceptable storage for a year at room temperature.

Examples 5, 6, 7, and 8

Latexes are prepared according to the general procedure, using 3 mol% vinyltriethoxysilane, and the indicated amount of shock absorber.

Example 5. This preparation is carried out without buffer, and the pH during the reaction is allowed to decrease from a pH initial of 4, which is reduced quickly within 15 minutes to less pH 3 for an additional 3.5 hours of reaction time.

Example 6. This preparation uses 0.15 grams of sodium bicarbonate buffer (0.10% in the aqueous phase.) The pH during the reaction is allowed to decrease from an initial pH of 8.5, which is rapidly reduced within 15 minutes at pH 6.5, and is reduced firm additionally at pH 2-3 at the end of the reaction.

Example 7. This preparation uses 0.2 grams of sodium bicarbonate buffer (0.13% in the aqueous phase.) The pH during the reaction is allowed to decrease from an initial pH of 8.5, it is rapidly reduced within 15 minutes of pH 5.5 to 6, and it Firmly reduce additionally to pH 2-3 by end of reaction

Example 8. This preparation uses 0.5 grams of sodium bicarbonate buffer (0.33% in the aqueous phase.) at the beginning. The pH during the reaction is allowed to decrease from a pH initial of 9, which reduces within 15 minutes to pH 8, and is reduced from firm manner additionally at pH 5.5-5 at the end of three hours of the monomer addition. An additional 0.3 is added grams of buffer at this point and the pH is 7 -7.5 until the end of reaction The total buffer is 0.8 grams, 0.53% in the aqueous phase

Under stricter conditions of discharge silane concentration (3 mol% vs. 2 mol%), the capacity of systems that terminates its reaction at pH substantially to provide good conservation life and good development in Cure test ambient temperature is decreased when Compare with samples made with 2 mol% silane. Since the Silanol condensation index is proportional to the table of the concentration of silanol groups, the maturity index crosslinked under storage (all other things are the same) would be increased by the ratio of 9 (i.e. 3 squares) to 4 (that is, 2 squares), that is, 225%. While example 5 It is clearly inferior in both as it is done and a one-year test,  Examples 6, 7, and 8 are all acceptable in proof "as is does. "It is interesting to note that following the panels for cure for 30, 40, or 50 days in ambient conditions gives better solvent resistance for example 8 than for examples 6 and 7. After one year, example 8 is clearly superior to Examples 5, 6, and 7.

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Examples 9 and 10

Latexes are prepared according to the general procedure, using 3 mol% vinyltriethoxysilane, and the indicated amount of shock absorber. Example 10 is prepared by duplicated, as 10a and 10b.

Example 9. This preparation is carried out without buffer, and the pH during the reaction is allowed to decrease from a pH initial of 1.64. After 15 minutes the pH is 1.54 to 1.69. After of one hour of the monomer addition, the pH is 1.26, and this remains strongly acidic during the rest of the reaction.

Examples 10a and 10b. These preparations use in duplicate 0.65 grams of sodium bicarbonate buffer (0.43% in the aqueous phase.) The pH during the reaction is left decrease from an initial pH of 9, it is quickly reduced within 15 minutes at pH 6.5, and stays 6 to 6.5 for the rest of the reaction.

Tests at room temperature are not carried conducted on these samples when done or in a year of storage. After 21 months of storage, 10 and 10b shows substantial superiority in MEK friction tests. In 33 months of storage, the superiority is still clear, even through films of Examples 10a and 10b that are fragile and fragmented in the gel test. At least 21 months of life are obtained from conservation.

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Example 11

A latex is prepared according to the general procedure, using only 0.5% vinyltriethoxysilane, and without shock absorber The pH profile is not measured, but is similar to that of Examples 1, 4, and 9, since the same procedure is followed. The reaction mixture is substantially acidic.

The data in example 11 is taken when and after 30 months. The latex does not crosslink excessively in 30 months, as evidenced by a consistent sample after extraction, but shows only 49% gel and only 50 MEK rubs after 7 days in the environment.

When the sample is made it also shows poor solvent resistance in 7 days: only 15 MEK rubs and 2 to 3 in the MEK stain test. These results show that you can produce stable systems, although with lower properties, by Reduce the amount of silane. This established property can be enough for some applications, but the cure film is not substantially solvent resistant. Not incorporated Enough silane

Comparative example one

A latex is prepared without a cushion and without silane "when done" the test shows only 10 MEK rubs after 7 days in the environment, and the test results of only 1 spot for acetone and MEK tests in 7 days. The samples aged are not tested, but no change in values is expected, because there is no chemical mechanism "of self-crosslinking "in the latex.

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TABLE 1

Data in Preparation and Test in Examples 1 to 11 and Comparative Example one

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TABLE 1 A-A Data in the Preparation and Testing of Examples 1 to 11 and Comparative Example 1 - Table 1 A-A

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TABLE 1A-B Cure data at room temperature in preparations Fresh Latex

4

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TABLE 1A-C Cure Data at Ambient Temperature in Preparations Latex 12 Months old

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TABLE 1A-D Cure data at room temperature in 21 Months old latex preparations

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TABLE 1A-E Cure data at room temperature in Latex preparations 33 Months old

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TABLE 1B ID and Latex Developments as a Control Sample for SAL - Table 1B-A

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TABLE 1B-B

9

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TABLE 1B-C

10

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Examples 12 and 13

In Examples 1 to 10, excessive hydrolysis of the alkoxy silane to release alcohol during latex preparation produces a latex that may be acceptable when done, but that deteriorates in storage, probably by crosslinking early. However, if the silane is not hydrolyzed at all During latex preparation, the properties will develop much more slowly, if done, after application. These Examples are synthesized using a different vinyl silane, vinyl tri-isopropoxysilane, which allows less hydrolysis Due to its structure. As long as it is not perfectly comparable in All forms of Examples 1 to 10, the data provide a strong indication that there is a lower limit for the amount of Hydrolysis that can occur during synthesis. In particular, a molten film at room temperature that has cured at only 4% of gel gives poor properties, and corresponds to the hydrolysis of only 19% of available alcohol. Even after cooking for strength of cure, 65% gel is soft, indicating poor crosslinking.

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Example 12. A latex is prepared according to The general procedure, using 3 mol% vinyl tri-iso-propoxysilane, instead of vinyltriethoxysilane, and without buffer. The pH profile is not measures, but is similar to that of examples 1, 4, and 9, since it follows The same procedure. The reaction mixture is substantially acidic

Example 13. This preparation also employs vinyl tri-iso-propoxysilane and it use 0.22 grams of sodium bicarbonate buffer (0.15%) in the aqueous phase. The pH during the reaction is allowed to carry it down from an initial pH of 8.5, it is rapidly reduced within 15 minutes at pH 6.5, and is further reduced to pH 2-3 at the end of the reaction. It improves poor development at room temperature by cooking, but the MEK friction tests are only acceptable even after cooking. Example 12, more completely hydrolyzed, cures at temperature atmosphere and gives good properties when cooking.

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TABLE 2 Correlation of the Degree of Hydrolysis with Properties Cure of Vinyl Modified Acrylic Latex Silanes

eleven

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In an embodiment of the invention as illustrated in the tables, an acceptable range of hydrolysis for latexes of this general composition and with a vinyl silane as the component silane is more than 19% hydrolysis to provide properties acceptable at room temperature curing. In another mode of the invention and for materials containing vinyltriethoxysilane, the upper limit is less than about 62% (Example 5).

Examples 14-16 - Scope of thermal initiation The above examples are all carried out. by the use of "redox initiation" to form the polymers of dispersion (latex). Redox initiation is a common technique, but "thermal initiation" is another scope for a modality of the invention. In examples 14-16, it is demonstrated thermal initiation and the results are given in the tables T-1 and T-2.

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I. Formulation used in the Examples 14-16 (Based on 300 grams total)

A. Water, optional buffer (sodium bicarbonate), surfactant (s) :

Deionized water

136.6 grams

Shock absorber sodium bicarbonate

quantities varied

Abex 2020

14.4 grams

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B. Monomers :

The monomers are selected in these examples. individuals to maintain a constant percentage of MAA, and a constant ratio of MMA to BA, when the content of silane Three and five mole percent of the silane monomer is used as examples There is no limited limitation involved in the process. For every 100 grams of monomers, the following are used relationships, are presented to allow you to easily see the Amount in percentage.

12

C. Initiator :

(NH 4) 2 S 2 O 8 0.38 grams (in 25 grams of aqueous solution)

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D. Shock absorber :

NaHCO 3 is used as 6.25% solution aqueous (to control the pH in approximately only 7).

In comparison to the experiments described in Examples 1-13, higher concentrations of silanes are used. Higher concentrations are more difficult to keep stable in storage, but the results in Examples 1-13 are good enough to encourage these experiments at levels greater than - 3 and 5 mol% - versus 1, 2, or 3% mol used in those examples. Higher silane levels have the potential to offer higher performance levels in the final coating or sealant prepared from the latex. An increase of 3% to 5% in the concentration of silane has the potential to increase the gelation of the reactions that lead to storage conditions of poor capacity by means of the ratio of the square of the concentrations that is 25 to 9 almost an increase of three times. Thus, the ability to include 5% silane is a main stage and a major change in the formulation. Other minor changes in formulation details will be apparent when considering the synthesis procedure shown below. A higher temperature than consistent thermal initiation is used.

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II. Synthesis - Examples 14-16

1. Deionized water (136.6 mL) is added to a 800 mL shirt reaction flask, and added with stirring Gentle 14.4 grams of the surfactant and 4 mL of bicarbonate solution of sodium (in the case of controlling the pH at sim7). The content they are heated at 75 ° C with fluid that transfers heat to temperature constant in the shirt while the flask is purged with N2. The N_ {2} cover is maintained throughout the series.

2. Silane and acrylic monomers (125.2 total grams) are mixed and transferred to an addition funnel separated.

3. The first portions of the monomer e initiator are added to the reaction flask. 10% of the mixture of monomer prepared in stage B (12.5 grams) and 20% of the solution of initiator (5 mL) are added to the reaction flask via two pumps separated over a period of approximately one minute. A light exotherm is usually noticed. The reaction is allowed to proceed at a temperature of 75 ° C for 15 minutes while maintaining Good agitation The reaction temperature is maintained within 2-3º to 75º during the following stages.

4. The rest of the monomer mixture (112.7 grams) and the initiator solution (20 mL) are continuously charged to through the pumps separated over a period of three hours.

5. The reaction mixture is allowed to stir. for another 30 minutes after the ones are completely added monomers and initiator.

6. The latex is allowed to cool to temperature ambient. The pH is adjusted to 7.5 using hydroxide solution of ammonium (<10% ac). The latex is filtered using a nylon sieve 200 mesh.

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III. Results (for examples 14-16)

The results are presented in two tables, Table T1 and Table T2.

Table T1 is for latexes prepared with 5 mol% vinyltriethoxysilane. This table is divided into sections, T1-A, T1-B, etc. This presents the synthesis training, the initial test information in latex when they prepare, and the test information after accelerating aging at 50 ° C for half a month and a month.

Table T2 presents the data obtained with the latex prepared with 3 mol% vinyltriethoxy silane. They show up synthesis data and test results for freshly prepared latex; data from Accelerated aging for this example.

Table T-1: In 5 mol% silane, the samples control at pH 7 during continuous polymerization (working examples 14 and 15, according to this invention) to provide a performance acceptable with ambient curing conditions after one month to 50ºC, simulating one year at room temperature. Those samples pH 3 to 4 preparations are clearly inferior (examples Comparatives Comp 2 and Comp 3, not prepared according to the invention). Comparative samples give poor results that they have 59 and 73% of the alcohol in the silanes released by hydrolysis; the good performance of the samples has 25% and 30% of the hydrolyzed silane as determined by measuring alcohol released.

Table T-2: Examination of the data in Table T-2 in 3 mol% silane shows that the pH is maintained at 5, versus 3, during synthesis, which provides a superior latex when it is prepared. The sample prepared in pH 3 is of poor quality when prepared; The sample prepared at pH 5 gives good results. The comparative samples give poor results that have 65 and 77% of the alcohol in the silanes released by hydrolysis; The sample of good performance has 24% of the hydrolyzed silane as determined by measuring the alcohol released. The data in this table are also compared with the examples for 5 mol% in Table T-1, where the data show the benefit of maintaining the pH near 7 during synthesis.

In examples 1-13, it is shown that a desirable level of hydrolysis during synthesis is less than 10% and less than about 60% for the compositions used, containing up to 3 mol% silane. In the examples 14-16, the samples that give good results are hydrolyze about 24 to 30% as measured by alcohol released; poorly performing samples have approximately 59 at 77% of the hydrolyzed silane, as determined by alcohol released. It is not reasonable that the current concentration of silane hydrolyzate is a measure more stability and performance water than is the fraction of the percentage of the amount (variable) of silane Present. At higher levels of incorporation as a percentage of silane, less hydrolysis (as a percentage of silane present) is you need to reach the same desirable absolute concentration of silanols, when compared to the hydrolyzed silane present in a lower level of%. The exact concentration of silanoles desired cannot be calculated precisely because they do not exist many variables to be considered at the end of the conditions of use.

Applications. In one embodiment of the invention, a coalescing system suitable for silylated latex has been found to have 2% butyl dipropylene glycol ether plus 4% 2- (2-Butoxyethoxy) - ethyl acetate based on the total weight of the latex that includes water. The formulation can be dispose of zinc phosphate or thermoplastic treated steel (to make a free film) for thick drying of approximately 1 thousand (25 Pm) and cured under the conditions of ambient or at elevated temperature, for several times.

The newly synthesized latexes are left remain at room temperature for at least 24 hours, Usually 2 to 3 days, and never more than 7 days before samples are taken for "uncured" trial.

A small sample of latex is mixed with 2% of butyl dipropylene glycol containing 4% 2- (2-Butoxyethoxy) ethyl acetate with base in the total weight of the latex that includes water. He is allowed to rest for 30 minutes This can be arranged under a steel panel phosphated to give a dry film thickness of about 1 thousand when using helical doser, number 24 (of the Company Gardner) This coated wand gives a wet film thickness of approximately 2.5 thousand.

Coating films are tested after loss that heal under ambient conditions for a certain time usually 7 days and 30 or 40 days. In some cases these are cook at 120 ° C for 20 minutes before testing or before curing additional environment before testing. Cooking it may represent some final conditions of use where the heat is acceptable, and this also causes master cure (formation of a network of crosslinked polymer) that cures the environment. This is useful for an understanding of the theoretical limits of itself and how much a system can be cured with limitation removed at temperature ambient.

Characterization of Silylated Acrylic Latexes and Properties of Coatings with Gel content: A sample exactly weighed (0.1 mg) of coating films is placed in a thin wire box in a Soxhlet extractor, and it is extracted with acetone at reflux for 8 hours. The weight loss of the Coating sample is measured exactly, with the content of gel calculated according to:

Content of gel (%) = (1- \ DeltaW / W_ {0}) x 100

Where:

W0 is the initial weight of the coating sample, and

- ΔW is the weight loss during solvent extraction.

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If the film breaks and fragments into small pieces, such as reticulated films, the content of gel cannot be measured because the film is retained incompletely by the mesh. This procedure is based on ASTM D2765-95.

MEK resistance: Double friction in accordance with ASTM D 4752-87, se modify to continue friction until the substrate is exposed, even if the number of double rubs is greater than the value of 50 as specified in the ASTM method.

Test of spotting: This test is carried out in accordance with ISO 2812-1974. One piece in square feet of paper Filter is put in the movie. Add eight drops of the solvent and The film is coated with a glass lens. In the case of acetone tests, the glass lens is removed after two minutes and the film is cleaned with a soft tissue paper. He result is the index from 1 to 5, with 1 removal that is complete, 2 which has substantially removed stains, and 5 has no effect. In In the case of MEK, the glass lens is removed after 30 minutes and the specimen is observed without cleaning.

Measurement of hydrolysis alcohol released during latex synthesis or after synthesis complexion: a distillation apparatus trap-trap (T-T) is used to separate latex solids from volatile components. He apparatus consists of a 250 mL flask, a tube that receives, and the U-connected tube with an outlet key in the bend of the tube in U. The sample size is 7 to 10 grams, typically 8 grams. The distillation procedure includes 4 stages Main:

one.

Pre-freezing: the sample is frozen by rotating the flask of the sealed sample on dry ice. A thin ice coating (cover) of the sample on the wall of the flask is formed by ensuring sufficient steam flow from the shows the condenser during subsequent distillation. This sharply accelerates distillation due to its greater area of frozen latex surface.

2.

Deep freezing: the flask of Sample adheres to the distillation apparatus, and the sample flask  partially submerged in liquid nitrogen to cool it additionally in preparation for distillation trap-trap The system is sealed to external air during this procedure

3.

Vacuum: The system is evacuated distillation with a mechanical pump at a pressure of approximately 0.05 mm Hg while the sample is kept at a temperature of liquid nitrogen.

Four.

Distillation: the system closes (under full vacuum) and the liquid nitrogen bath is removed from the flask  of sample and moves to the tube it receives. How the sample is heats slowly, the volatiles evaporate and condense in the cold tube it receives. Complete distillation is considered when the Sample is a dry white powdery solid.

A gas chromatography (Hewlett Packard 5890 series II) equipped with a capillarity column packed with cross-linked phenyl / methyl siloxane (DB5, Agilent) and the FID detector to analyze distilled samples. Techniques GC-MS spectrometers are used to identify Separate species To quantitatively determine the alcohol content in liquid distilled samples, a heavy amount of 2,4-dioxane as the standard internal after distillation is complete.

While the invention has been described as as it appears above, many modifications can be made to adapt a particular or material situation to the teachings of the invention without departing from its essential scope.

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TABLE 1 Characteristics of Silage Acrylic Latex Prepared with the Thermal Initiation System

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TABLE T1-A Synthesis of 5 mol% of the Latex Silylated

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TABLE T1-B Characterization and Test Results of the latex 5 mol% silylates Prepared

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TABLE T1-C Test results of 5 mol silylated latex Half-Month Age in 50 Celsius Degrees and without cooking

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TABLE T1-D Results of 5 mol% Silage Latex Test at the age of one month at 50 degrees Celsius and without cooking

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TABLE 2 Characteristics of Silage Acrylic Latex 3 mol% Prepared with an Initiation System Thermal

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TABLE T2-B Results of the 3 mol% Latex Test Freshly prepared without cooking

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Claims (11)

1. A process for preparing a silane modified (meth) acrylic latex interpolymer composition comprising continuously adding at least a portion of a mixture comprising at least 0.5 mol percent of a vinyl silane comprising hydrolysable groups and up to 99.5 mol percent of a monomer
(meth) acrylic for water and a surfactant in a reaction vessel, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 to through the reaction, while simultaneously hydrolyzing about 10 to about 60% of the vinyl silane hydrolyzable groups. 2. The process of claim 1 wherein the polymerization initiator is a redox initiator. 3. The process of claim 1, wherein The polymerization initiator is a thermal initiator. 4. The process of claim 1, wherein the polymerization initiator is selected from the group consisting of peroxides, azo compounds; inorganic persulfates; peracetate t-butyl; isopropyl peroxycarbonate; persulfate bisulfite; chlorate bisulfite, peroxide iron, persulfate-mercaptan, and their combinations. 5. The process of any of the claims 1-4, wherein the vinyl silane which comprising hydrolysable groups is selected from the group consisting of vinyltriethoxysilane and vinylmethyldiethoxysilane, and the monomer (meth) acrylic is selected from the group consisting of methyl methacrylate, butylacrylate, methacrylic acid, and mixtures thereof. 6. The process of any of the claims 1-5, wherein the shock absorber is sodium bicarbonate used at a level of approximately 0.4% at about 0.7% of the aqueous phase, and at least one polymer Organic vinyl is vinyl acetate. 7. The process of any of the claims 1-6, wherein the mixture comprises additionally up to about 20% by weight of at least one organic vinyl polymer. 8. A silane modified (meth) acrylic latex interpolymer composition prepared by a process comprising continuously adding at least a portion of a mixture comprising at least 0.5 mol percent of a vinyl silane comprising hydrolysable groups and up to 99.5 mol percent of a monomer
(meth) acrylic in water and a surfactant in a reaction vessel, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 to through the reaction, while simultaneously hydrolyzing about 10 to about 60% of the vinyl silane hydrolyzable groups. 9. The composition of claim 8, in where vinyl silane is selected from the group consisting of vinyltriethoxysilane and vinylmethyldiethoxysilane; the monomer (meth) acrylic is selected from the group consisting of methyl methacrylate, butylacrylate, methacrylic acid, and mixtures thereof; he buffer is sodium bicarbonate, it is used at a level of about 0.4% to about 0.7% of the aqueous phase; and the mixture further comprises up to about 20% by weight of at least one organic vinyl polymer. 10. An interpolymer composition that understands:

to)

by at least about 0.5 mol percent of a functional group vinyl alkoxysilane in which approximately 10 have been hydrolyzed to about 60% of the alkoxy groups; and, corresponding with this,

b)

until approximately 99.5 mol percent of at least one group functional (meth) acrylic selected from the group consisting of methyl methacrylate, butylacrylate, methacrylic acid, and their mixtures

11. The composition of any of the claims 8-10, wherein said composition is long storage for at least six months at temperature ambient.